碳纳米管修饰气体扩散电极高效电化学还原CO_(2)

Carbon Nanotubes Modified Gas Diffusion Electrode for Efficient Electrochemical Reduction of CO_(2)

电化学还原CO_(2)可利用可再生能源实现CO_(2)转化,是实现碳中和目标的重要支撑,但目前其反应器存在法拉第效率较低和槽电压较高等问题,严重制约其发展。本文用碳纳米管修饰催化层从而构建了新型气体扩散电极,研究发现添加碳纳米管后电极在200 mA·cm^(-2)的电流密度下CO法拉第效率最高可达93%,槽电压仅为-2.42 V,相较未添加碳纳米管的电极法拉第效率提高了13.7%,槽电压降低了240 m V,传荷阻力减小了29.4%。其主要原因是碳纳米管交错所形成的疏水三维骨架网络不仅有利于催化剂颗粒的分散,还有利于催化层孔隙率的提升和CO_(2)传输的增强。

Electrochemical reduction of CO_(2)(CO_(2) RR)combined with renewable energy is a promis-ing technology for carbon neutrality.The current reactors for CO_(2) RR face challenges of low faradic efficiency(FE)and high cell voltage,especially at high current densities.Here we report a gas diffu-sion electrode(GDE)modified with Ag nanoparticles and carbon nanotubes(CNTs)for CO_(2) RR.It showed that the FE of the electrode modified CNTs reached 93% at 200 mA·cm^(−2) with a cell voltage of−2.42 V.Compared to the electrode without CNTs modification,the FE increased by 13.7%while the cell voltage reduced by 240 mV.It was probably because the hydrophobic three-dimensional skeleton network formed by CNTs not only increase the dispersion of catalyst particles,but also enhance the CO_(2) transport for CO_(2) RR.